The objective of this project is to conduct descriptive studies of cancer incidence and mortality to identify leads for further research and to test hypotheses about cancer etiology. Efforts this year included evaluation of the impact of water fluoridation on cancer incidence and mortality; identification of increases in the incidence of adenocarcinoma of the esophagus and gastric cardia, particularly among white males; description of the patterns of childhood leukemia, multiple myeloma, lung cancer by histologic type, and trends in colon cancer, vulvar cancer, and non-Hodgkin's lymphoma; quantification of the impact of known factors on the non-Hodgkin's lymphoma trends; estimation of the prevalence of cancer in the United States; investigation of the accuracy of death certificates with respect to colorectal cancer deaths and the impact on observed mortality trends; updating of the descriptive epidemiology of several cancers, including the oral cavity, esophagus, kidney, bladder, and all cancers combined. Current work is focusing on the incidence patterns of colorectal cancer by subsite, non-Hodgkin's lymphoma by histologic type, and several other forms of cancer.